scholarly journals Method and device for the control of surface properties of porous solids at the boundary of their contact with liquids and gases

2021 ◽  
pp. 55-59
Author(s):  
Myroslava Chuiko ◽  
Lidiia Vytvytska ◽  
Nataliia Pindus
Keyword(s):  
Contact Angle ◽  
Surface Properties ◽  
Solid Body ◽  
Porous Body ◽  
Direct Contact ◽  
Contact Angle Hysteresis ◽  
Porous Solid ◽  
Porous Solids ◽  
Adhesive Interaction ◽  
Wetting Process

The article indicates the relevance of the problem of controlling the surface properties of solids, analyzes the features of interaction between porous solids in direct contact with liquids. The process of adhesive interaction of the system “liquid – porous solid” at the interface of these phases is analyzed and the dependence of the degree of wetting by a liquid of the surface of a solid on the structure of the porous body and the surface properties of the liquid is established. The dependence of the contact angle hysteresis of the solid with liquid on the porosity and roughness of the sample of the controlled body is substantiated. A method of complex express control of the wetting process, which consists in determining the hysteresis of fluid flowing in and out from the surface of a solid body, has been proposed. The method consists in determining the rate of liquid outflow from a tilted sample of a solid. At the same time, the liquid is applied with the same speed to the surface of a porous body sample. The design of device for realization of the method has been developed.

CHARACTERIZATION OF DYNAMIC WETTING OF PLASMA-TREATED PTFE FILM

2007 ◽  
Vol 14 (04) ◽  
pp. 821-825 ◽  
Author(s):  
Q. F. WEI ◽  
Y. LIU ◽  
F. L. HUANG ◽  
S. H. HONG
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Surface Properties ◽  
Contact Angle Hysteresis ◽  
Frictional Coefficient ◽  
Dynamic Contact Angle ◽  
Contact Angles ◽  
Dynamic Wetting ◽  
Ptfe Film ◽  
Receding Contact

Polytetrafluoroethylene (PTFE) has been increasingly used in many industries due to its low frictional coefficient and excellent chemical inertness. The surface properties of PTFE are of importance in various applications. The surface properties of PTFE can be modified by different techniques. In this study, PTFE film was treated in oxygen plasma for improving surface wettability. The effects of plasma treatment on dynamic wetting behavior were characterized using Scanning Probe Microscopy (SPM), Fourier transform infrared spectroscopy (FTIR), and dynamic contact angle (DCA) measurements. SPM observations revealed the etching effect of the plasma treatment on the film. The introduction of hydrophilic groups by plasma treatment was detected by FTIR. The roughened and functionalized surface resulted in the change in both advancing and receding contact angles. Advancing and receding contact angles were significantly reduced, but the contact angle hysteresis was obviously increased after plasma treatment.

A NEW APPROACH TO INVESTIGATE CONTACT ANGLE HYSTERESIS

2018 ◽  
Author(s):  
Qiao Liu ◽  
Abbasali Abouei Mehrizi ◽  
Hao Wang
Keyword(s):  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
New Approach

Drop impact on solids: contact-angle hysteresis filters impact energy into modal vibrations

2021 ◽  
Vol 923 ◽  
Author(s):  
Vanessa R. Kern ◽  
Joshua B. Bostwick ◽  
Paul H. Steen
Keyword(s):  
Contact Angle ◽  
Impact Energy ◽  
Contact Angle Hysteresis ◽  
Drop Impact

Abstract

scholarly journals An inversion of contact angle hysteresis when a liquid drop slides up on an inclined plane under the spark discharge action

2021 ◽  
Vol 33 (6) ◽  
pp. 061707
Author(s):  
Alexander E. Dubinov ◽  
Djamilya N. Iskhakova ◽  
Valeria A. Lyubimtseva
Keyword(s):  
Contact Angle ◽  
Liquid Drop ◽  
Contact Angle Hysteresis ◽  
Spark Discharge ◽  
Inclined Plane

scholarly journals Biomimetic Approach for the Elaboration of Highly Hydrophobic Surfaces: Study of the Links between Morphology and Wettability

Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Quentin Legrand ◽  
Stephane Benayoun ◽  
Stephane Valette
Keyword(s):  
Contact Angle ◽  
Ginkgo Biloba ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Textured Surfaces ◽  
Replication Process ◽  
Wetting Behavior ◽  
Static Contact ◽  
Biomimetic Approach ◽  
Highly Hydrophobic

This investigation of morphology-wetting links was performed using a biomimetic approach. Three natural leaves’ surfaces were studied: two bamboo varieties and Ginkgo Biloba. Multiscale surface topographies were analyzed by SEM observations, FFT, and Gaussian filtering. A PDMS replicating protocol of natural surfaces was proposed in order to study the purely morphological contribution to wetting. High static contact angles, close to 135∘, were measured on PDMS replicated surfaces. Compared to flat PDMS, the increase in static contact angle due to purely morphological contribution was around 20∘. Such an increase in contact angle was obtained despite loss of the nanometric scale during the replication process. Moreover, a significant decrease of the hysteresis contact angle was measured on PDMS replicas. The value of the contact angle hysteresis moved from 40∘ for flat PDMS to less than 10∘ for textured replicated surfaces. The wetting behavior of multiscale textured surfaces was then studied in the frame of the Wenzel and Cassie–Baxter models. Whereas the classical laws made it possible to describe the wetting behavior of the ginkgo biloba replications, a hierarchical model was developed to depict the wetting behavior of both bamboo species.

Increasing Storage Modulus, Contact Angle and Surface Tension of Airway Mucus Increases Clearance by Simulated Cough Through a Model Trachea

2010 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Storage Modulus ◽  
Surface Properties ◽  
Respiratory Diseases ◽  
Interactive Effects ◽  
Altered Surface ◽  
Human Trachea ◽  
Tension Increase ◽  
And Storage

Altered surface and viscoelastic material properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effects of the surface properties (contact angle and surface tension) and storage modulus with relatively unchanged viscosity on displacement of the simulated mucus aliquot during simulated cough through a model adult human trachea is investigated. For the mucus simulants used in this study contact angle and surface tension increase significantly as storage modulus increase while viscosity remains practically unchanged. Displacement of mucus simulant aliquots increased significantly with increasing storage modulus (and contact angle) at a given cough velocity in the range between 5 meters/second (m/s) and 30 m/s with duration 0.3 s. Results suggest that the interactive effects of elasticity and surface properties may help facilitate mucus displacement at low cough velocities.

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